Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for indicating skipping of access class barring (ACB) in a wireless communication system.
Related Art
Universal mobile telecommunications system (UMTS) is a 3rd generation (3G) asynchronous mobile communication system operating in wideband code division multiple access (WCDMA) based on European systems, global system for mobile communications (GSM) and general packet radio services (GPRS). A long-term evolution (LTE) of UMTS is under discussion by the 3rd generation partnership project (3GPP) that standardized UMTS.
The 3GPP LTE is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.
Internet protocol multimedia subsystem (IMS) multimedia telephony communication service allows multimedia conversational communication between two or more end points. An end point is typically located in a user equipment (UE), but can also be located in a network entity. As for traditional circuit-switched telephony, the protocols for the IMS multimedia telephony communication service allow a user to connect to any other user, regardless of operator and access technology. The IMS multimedia telephony communication service consists of two principal parts, which are a basic communication part, and an optional supplementary services part.
Various access control schemes may be defined in 3GPP LTE, one of which is a service specific access control (SSAC). For example, SSAC for the IMS multimedia telephony communication service may be performed. Further, for the specific application/service, access class barring (ACB) may be skipped. A method for indicating skipping of ACB for the specific application/service may be required.